Yealink Forum has finished the update on 25th November so that users can use their own Forum’s account to login Yealink support and Ticket directly . After this update, all users of Yealink Forum won’t be able to login to their accounts by using original username. New system requires email address which you used to apply for your account to replace your original username. Password stays the same.

For example:
You used username/password (marylouis/123456) to login before.
Now you need to use email/original password (marylouis@gmail.com/123456) to login.

If you don't know the email you used for applying for the account, please send email to support@yealink.com.

BTW: if you not logged in to the forum and want to reply directly to a post with the “Reply” or “New Reply” button you are going to the old login screen, but can’t login.
You can only login with the “Login” button on top of the screen.